Please help me again in my physics pronlem (momentum--energy transfer), tnx!?

Question

A 10-kg iron ball rolling at 2 m/s on a horizontal surface strikes a 1.0-kg wooden ball of the same size that is at rest. What is the speed of each ball after the collision? What proportion of the iron ball’s original KE was transferred to the wooden ball?

Answer 1

P(before ) = P(after)
m1V1+m2V2=m1V'1 + m2V'2
V2=0
We have
m1V1=m1V'1 + m1V'2

also using Ke equation
0.5 m1(V1)^2= 0.5 m1(V'1)^2 + 0.5m2(V'2)^2
or the Ke equation becomes
m1V1^2= m1(V'1)^2 + m2(V'2)^2

from first we know that
V'2= [m1V1 - m1V'1]/m2

sustitute into Ke equation and solve for V'1 and then solve for V'2